This invention relates to a turning device for an automated press line of the type where workpieces are turned after being withdrawn from a working chamber of a press and are then subsequently fed to a further press.
A turning device is known from DOS (German Unexamined laid-open-application) No. 1,552,592 and the corresponding U.S. Pat. No. 3,342,125 which is arranged between presses of an automated press line. In this system, workpieces are removed by means of unloading devices from the working chamber of a press and are transferred to a belt-type conveyor. The belt-type conveyor bridges the interspace between two presses and constitutes a transportation plane. Turning devices are arranged in mutual symmetry on both sides of the transportation plane formed by the belt-type conveyor. In this connection, the turning devices are fashioned as four-armed stars, recesses being provided in the end zone of each arm; the contours of these recesses being adapted to the workpieces to be turned. During operation, the workpieces to be turned are conveyed by the belt-type conveyor into the recesses of the turning elements, turned by 180 angular degrees by a rotation of the turning elements, deposited on the belt-type conveyor, transported, and fed to the working chamber of the subsequent press by means of loading devices. This conventional turning device requires a belt-type conveyor and turning elements fashioned in correspondence with the workpieces to be produced. Consequently, when the workpiece is altered, the turning elements must be exchanged.
This invention contemplates providing a turning device which is simpler in its structure than the above-mentioned apparatus and which can be used almost universally.
Preferred embodiments of this invention provide a turning device with (i) reversing gripper means having two separate gripper arms and clamp means movable with said gripper arms for selectively clamping a workpiece therebetween; (ii) a separately controllable gripper arm operating means for controlling the movement of each of the gripper arms, and (iii) rotating unit means for rotatably moving the gripper means, inclusive of the gripper arms and associated operating means. Preferably, each gripper arm is pivotably movable about the rotation axis of the rotary unit means by at least 90.degree., independantly of the other gripper arm, in order to accommodate transfer and turning of the workpiece. In the preferred embodiment described more fully hereinafter, the gripper arms are actuated by fluid operated piston means which are connected to respective fluid force supplies by way of a rotatable connection. To accommodate adjustment of the position of the gripper arms and the rotatable unit, preferred embodiments include adjustable connections therebetween as described more fully below.
The advantages inherent in a turning device according to this invention are to be seen particularly in the avoidance of belt-type conveyors, roller conveyors, or the like between the presses of an automated press line. Thereby, the distance of the presses of the automated press line with respect to one another can be reduced, resulting in a space-saving arrangement. The turning devices can be adapted to almost any workpiece to be turned, without having to effect an exchange. Furthermore, it is possible by means of a turning device in accordance with this invention to pivot the workpieces to be turned into any desired position.
Reference may be made to certain prior art devices which disclose particular features of the various structures which are to be combined in practicing this invention. For example, DOS No. 2,202,005 describes a transfer device for the transportation of workpieces wherein grippers are mounted on both sides of a transporting plane in mutual symmetry and with similar functions. Furthermore, a gripper is known from U.S. Pat. No. 3,400,836 wherein the two gripper arms can be opened up by means of an actuating element simultaneously by at least .+-. 90 angular degrees. U.S. Pat. No. 3,371,953 shows a gripper with two jaws mounted on a common fulcrum. A turning gripper per se is known from German Pat. No. 1,922,714 (especially FIG. 20). Finally, attention is directed to U.S. Pat. No. 2,757,037 wherein a gripper is disclosed, the jaws of which are movable by means of respectively one double-acting cylinder-piston unit. However, these prior-art arrangements do not contain any suggestion with respect to the solution according to the present invention.